Apparatus for sorting out defective ones from a continuous supply of moldings of bottomed cylindrical shape such as cups

ABSTRACT

Moldings to be sorted are successively loaded on a first passageway at a receiving end thereof, with the bottomed end of each molding directed upward, and are caused to slide toward the exit end of the passageway. This first passageway has a first air outlet formed in its bottom surface at a point intermediate between both ends thereof for delivering air at a prescribed pressure into each of the moldings passing thereover, and a second air outlet is also provided which delivers as required a forced current of air across the first passageway to direct either defective or non-defective moldings into a second passageway branching off from the first passageway. Both the first and second air outlets are associated with a pneumatic circuit such that in the particular embodiment disclosed herein, only non-defective moldings are directed into the second passageway while defective ones are allowed to pass on toward the exit end of the first passageway.

United States Patent Sakai 5] Nov. 25, 1975 APPARATUS FOR SORTING OUTDEFECTIVE ONES FROM A CONTINUOUS SUPPLY OF MOLDINGS OF BOTTOMEDCYLINDRICAL SHAPE SUCH AS CUPS Appl. No.: 415,554

3,716,123 2/1973 Becker 209/80 Primary Examiner-Allen N. KnowlesAttorney, Agent, or Firm-Wenderoth, Lind & Ponack [57] ABSTRACT Moldingsto be sorted are successively loaded on a first passageway at areceiving end thereof, with the bottomed end of each molding directedupward, and are caused to slide toward the exit end of the passageway.This first passageway has a first air outlet formed in its bottomsurface at a point intermediate between both ends thereof for deliveringair at a prescribed pressure into each of the moldings passingthereover, and a second air outlet is also provided which delivers asrequired a forced current of air across the first passageway to directeither defective or non-defective moldings into a second passagewaybranching off from the first passageway. Both the first and second airoutlets are associated with a pneumatic circuit such that in theparticular embodiment disclosed herein, only non-defective moldings aredirected into the second passageway while' defective ones are allowed topass on toward the exit end of the first passageway.

4 Claims, 1 Drawing Figure US. Patent Nov. 25, 1975 3,921,808

APPARATUS FOR SORTING OUT DEFECTIVE ONES FROM A CONTINUOUS SUPPLY OFMOLDINGS OF BOTTOMED CYLINDRICAL SHAPE SUCH AS CUPS BACKGROUND OF THEINVENTION This invention relates to an apparatus for pneumaticallysorting out defective ones from a continuous supply of moldings ofbottomed, substantially cylindrical shape such as cups, caps, knobs andthe like. All such moldings to be sorted by this apparatus will bereferred to simply as bottomed cylindrical objects throughout the restof this specification and in the claims appended hereto, although theymay not be exactly cylindrical in shape.

Synthetic resin moldings, in particular, are subject to varieties ofdefects such as pinholes, cavities and deformations that are produced atthe time of their manufacture, due for example to the insufficientheating of the material or to the malfunctions of the injection nozzle.Such defective products must of course be sorted out from non-defectiveones prior to shipment. Conventionally, this sorting operation has beenperformed either manually or by means of sorting machines of the typehaving an indexed rotary table. Manual sorting operation is of courseundesirable in view of the expenses in time and labor involved and ofinevitable sorting errors. The rotary table-type sorting machines arealso subject to the objection that they are highly expensive and,moreover, are capable of sorting articles of prescribed shape and sizeonly.

SUMMARY OF THE INVENTION In view of the noted deficiencies of the priorart, it is an object of this invention to provide an apparatus forpneumatically sorting out defective ones from a continuous supply ofbottomed cylindrical objects, such that the apparatus is easilyadaptable for use with the objects of considerably varied shape andsize.

Another object of the invention is to provide an apparatus of thecharacter described, which is simple and inexpensive in construction andwhich is so compact in size that it can easily be installed in amanufacturing plant substantially as an integral part of the moldingequipment.

With these objects in view and the other objects hereinafter madeapparent, this invention provides an apparatus comprising a firstpassageway extenting generally rectilinearly, and a second passagewaybranching off therefrom. Bottomed cylindrical objects to be sorted aresuccessively loaded on the first passageway at a receiving end thereof,each with its bottomed end directed upward, and are caused to traveltoward the exit end of the passageway either by gravity, by forcedcurrents of air, or by any other suitable feed mechanisms. A first airoutlet is formed in the bottom surface of the first passageway at apoint on the upstream side of the point where-the second passagewaybranches off, and a second air outlet is formed substantially inconfronting relationship to the entrance of the second passageway.

Both the first and second air outlets are parts of a pneumatic circuitsuch that air is constantly flowing out of the first air'outlet at aprescribed, perhaps extremely low, pressure into each of the bottomedcylindrical objects traveling thereover. According to a particularembodiment disclosed hereinbelow, a back pressure arising each time anon-defective object passes over the 2 first air outlet is sensed bymeans included in the pneumatic circuit, and a control valve is thenopened to permit a forced current of air to be delivered out of thesecond, air outlet across the first passageway thereby 5 directing thenon-defective object into the second passageway. No substantial backpressure develops in case defective objects pass over the first airoutlet, and these are allowed to travel to the exit end of the firstpassageway.

According to one experimental model actually constructed on the basis ofthe above summarized inventive concepts, it has been possible'to'continuously sort articles with a capacity of about 30 cubic centimetersat a rate of up to about 300 per minute, with a defect of down to about1 square millimeter detected exactly.

The features which are believed to be novel and characteristic of thisinvention are set forth with particularity in the appended claims. Theinvention itself, however, both as to its organization and mode ofoperation, together with the further objects and advantages thereof,will be best understood from the following description taken inconjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The accompanying drawing illustrates,partly in perspective and partly in the form of a block diagram, apreferred embodiment of this invention.

DESCRIPTION OF- THE PREFERRED EMBODIMENT As seen in the drawing, theapparatus according to the invention includes a casing 10 adapted toencase various means constituting a pneumatic circuit and so forth, thepneumatic circuit being represented in the form of a block diagram inthe same drawing. A first passageway 11 for a continuous stream ofbottomed cylindrical objects 12 is defined generally rectilinearly onthe top of the casing 10 by a pair of guides 13 serving as side walls ofthe passageway. Although not clearly seen in the drawing, it is assumedthat the first passageway 1 1 is set at a suitable angle to the plane ofthe horizon so that the successive bottomed cylindrical objects 12 arefed by gravity from the receiving end to the exit end, both not shown,of the passageway. It is therefore desirable that the surfaces definingthis first passageway 11 be so smooth that no substantial frictionalresistance is offered to the sliding motion of the bottomed cylindricalobjects 12.

A further guide 14 in the form of a sheet of stainless steel or the likebent into the shape of an L is fastened to the front face of the casing10 in order to readjust, if necessary, the positions of the successivebottomed cylindrical objects 12 as they are fed along the firstpassageway 1 l. The position of this guide 14 relative to the bottomsurface of the first passageway 11 is adjustable by the manual turn ofthumbscrews 15 on bolts 16 that are inserted through respective slots 17of the guide 14.

The first passageway 11 has a first air outlet 18 formed in its bottomsurface in a position intermediate between both extremities thereof, orperhaps in a position closer to the exit end of the passageway situatedto the right as seen in the drawing. Air is constantly flowing out ofthis first air outlet at an extremely low pressure, as hereinafterreferred to in more detail. A pressurizingfeed roll 19 made for exampleof rubber of suitable hardness is revolvably mounted above the first airoutlet 18 in order to feed the successive bottomed 3 cylindrical objects12 in close sliding contact with the bottom surface of the firstpassageway l l as they travel over the first air outlet 18.

The pressurizing feed roll 19 is in constant rotation, being fixedlymounted on one end of a shaft 20 revolvably supported by a pair ofbearings 21 and driven by an electric motor 22 via an endless belt 23running over a pair of terminal pulleys 24. Although not shown in thedrawing, it is assumed that at least the bearings 21 are supported on amount which is movable up and down in order to adjust the position ofthe roll 19 relative to the bottom surface of the first passageway 11 inaccordance with the height of the various bottomed cylindrical objectsto be sorted by this apparatus.

A second air outlet 25, preferably with a nozzle constriction, isprovided through one of the lateral guides 13 of the first passageway l1 in a position on the downstream side of the first air outlet 18 and ata prescribed distance therefrom. Air under pressure is to be deliveredout of this second air outlet 25 across the first passageway 1 1whenever required, such that a desired one of the bottomed cylindricalobjects 12 which has just emerged from under the pressurizing feed roll19 is sent out into a second passageway 26 branching off from the firstpassageway 11 at a suitable angle thereto. This second passageway 26 mayalso be set at an angle to the plane of the horizon to make possible thegravity feed of the objects which have been fed therein by the forcedcurrent of air from the second air outlet 25.

For delivering air out of the first and second air outlets 18 and 25 asaforesaid, a source of compressed air is provided at 27 in which air iscompressed to a pressure of, say, from about 3 to 10 kilograms persquare centimeter. This compressed air from the source 27 is deliveredvia a stop valve 28 to a filter 29 where the air is separated from itswater, oil and other undesirable contents. The thus-filtered air isdirected, on the one hand, to a precision pressure regulator 30 wherethe pressure of the air is reduced to, say, about 0.2 kilogram persquare centimeter. The air of this reduced pressure is then delivered tothe first air outlet 18 via a metering valve 31 and a conduit 32.

The air from the filter 29 is directed, on the other hand, to a highpressure regulator 33 where the pressure of the air is regulated to avalue within the range of, say, from about 2 to 3 kilograms per squarecentimeter, The air of this. pressure range is then delivered, asrequired, to the second air outlet 25 at the end of a conduit 34 via acontrol valve 35 of the type represented symbolically in the drawing.

The operation of this control valve 35 is under the control of a circuit36 of well known construction based on the principles of fluidics(hereinafter referred to as the fluidic circuit). This fluidic circuit36 is communicated via a pneumatic amplifier 37 with the aforesaidconduit 32 leading to the first air outlet 18.

Although not essential to this invention, the fluidic circuit 36 can becommunicated with an electropneumatic transducer 38 which in turn isconnected to a counter 39 of well known type that produces an outputpulse each time it receives a preassigned number of input pulses. Thecounter 39 can be further connected to a totalizing counter 40 capableof registering and visually indicating a total number of the outputpulses from the counter 39. Furthermore, air gauges 41 and 42 may beequipped to the conduits 43 and 44 extending between the precisionpressure regulator 30 and the metering valve 31 and between the highpressure regulator 33 and the control valve 35, respectively, to permitvisual observation of the pressures of the air streams flowing out ofthe respective pressure regulators 30 and 33.

In the operation of this preferred embodiment of the invention, thebottomed cylindrical objects to be sorted are successively loaded on thefirst passageway 11 at the receiving end thereof by any suitable means,not shown, in such a manner that each object is placed with its bottomedend directed upward as seen in the drawing. Fed by gravity along thefirst passageway 11 in a substantially streamlined manner, thesuccessive bottomed cylindrical objects 12 travel under the guide 14 andreach the first air outlet 18, in which position each object is presseddown against the bottom surface of the first passageway by thepressurizing feed roll 19 so that the airflowing out of the first airoutlet at an extremely low rate will not escape through any negligibledegree of deformation or irregularity at the lower edge of the object.

Thus, in case the particular bottomed cylindrical object traveling overthe first air outlet 18 is non-defective, a back pressure develops tosuch an extent that a reversed flow of air takes place through theconduit 32. This reversed air flow is unable to pass through themetering valve 31 and is, instead, directed into the amplifier 37, whichamplifier is effective to produce an output signal in response to suchback pressure of not less than a prescribed value. This output signalfrom the amplifier 37 is delivered to the fluidic circuit 36, whichcircuit then operates to open the control valve 35 and hence to permitair under pressure to be delivered out of the second air outlet 25.Since then the aforesaid non-defective bottomed cylindrical object isalready released from the pressurizing feed roll 19, the object will beblown out into the second passageway 26 and will succeedingly travelalong the same by gravity to be deposited in a receptacle or the like,not shown, at the exit end of this second passageway.

On the other hand, in case the bottomed cylindrical object travelingover the first air outlet 18 is defective, the air flowing from thefirst air outlet will bleed through the defective part or parts of theobject. No substantial back pressure develops in this case, so that thedefective object is allowed to travel past the second air outlet 25 andis caused to drop into a receptacle or the like, also not shown, at theexit end of the first passageway 11.

It will be apparent that the counter 39 produces its output signal eachtime it counts a predetermined number of nondefective bottomedcylindrical objects 12. This counter output signal can be utilized forthe automatic control of the succeeding packaging operation or the like.

While the various objects of the invention, either explicitly stated orotherwise setforth, are believed to be fully accomplished by thepreferred embodiment disclosed herein, it will be easy for those skilledin the art to devise many modifications or changes of such specificallyrecited embodiment. For instance, instead of directing non-defectivebottomed cylindrical objects into the second passageway 26 by the forcedcurrent of air from the second air outlet 25 as in the foregoingdisclosure, the pneumatic circuit represented in the form of a blockdiagram in the accompanying drawing can easily be so modified that onlydefective objects will be guided into the second passageway. Moreover,while in the illustrated embodiment of the invention the successivebottomed cylindrical objects 12 are fed by gravity along the first andsecond passageways 11 and 26, the same object can of course beaccomplished by belt conveyors, by roll conveyors, by forced currents ofair. or by any other similar feed mechanisms.

All such modifications, substitutions or changes are intended in theforegoing disclosure. It is therefore appropriate that the invention beconstrued broadly and in a manner consistent with the fair meaning orproper scope of the invention as sought to be defined by the followingclaims.

I claim:

1. An apparatus for sorting out defective ones from a continuous supplyof bottomed cylindrical objects, comprising in combination:

a first passageway for the bottomed cylindrical objects having areceiving end and an exit end, said bottomed cylindrical objects beingsuccessively loaded on said first passageway at said receiving endthereof in such a manner that each of said bottomed cylindrical objectsis placed with its bottomed end directed upward;

means for successively feeding said bottomed cylindrical objects alongsaid first passageway from said receiving to said exit end thereof;

a first air outlet formed in the bottom surface of said first passagewayat a point intermediate between said receiving and said exit endthereof, said first air outlet being adapted to ascertain the presenceof any defect in each of said bottomed cylindrical objects travelingthereover by delivering air therein at a prescribed pressure;

a second passageway branching off from said first passageway at a pointon the downstream side of said first air outlet;

a second air outlet for delivering a forced current of air across saidfirst passageway whereby said bottomed cylindrical objects can bedirected into said Second passageway; and

a pneumatic circuit associated with said first and second air outlets,said pneumatic circuit being effec- 6 tive to cause said second airoutlet to direct only a predetermined one of defective and non-defectiveclasses of said bottomed cylindrical objects into said second passagewaywhile the other class of said bottomed cylindrical objects are allowedto travel to said exit end of said first passageway.

2. The apparatus as recited in claim 1, wherein said pneumatic circuitcomprises:

a source of compressed air;

first pressure regulating means for regulating the pressure of the airfrom said source;

a first conduit communicating said first pressure regulating means withsaid first air outlet;

second pressure regulating means for regulating the pressure of the airfrom said source;

control valve means communicated with said second pressure regulatingmeans, said control valve means being normally closed;

a second conduit communicating said control valve means with said secondair outlet; and

fluidic circuit means effective to open said control valve means inresponse to the development of a back pressure in said first conduit;

whereby only non-defective ones of said bottomed cylindrical objects aredirected into said second passageway by the forced current of airdelivered out of said second air outlet.

3. The apparatus as recited in claim 1, further including pressurizingfeed means for feeding each of said bottomed cylindrical objects atleast over said first air outlet in close sliding contact with thebottom surface of said first passageway, said pressurizing feed meanscomprising a roll rotatably supported above said first passageway, anddrive means for imparting rotation to said roll.

4. The apparatus as recited in claim 3, wherein the position of saidroll is variable toward and away from the bottom surface of said firstpassageway to adjust to the varied height of the bottomed cylindricalobjects to be sorted by the apparatus.

1. An apparatus for sorting out defective ones from a continuous supply of bottomed cylindrical objects, comprising in combination: a first passageway for the bottomed cylindrical objects having a receiving end and an exit end, said bottomed cylindrical objects being successively loaded on said first passageway at said receiving end thereof in such a manner that each of said bottomed cylindrical objects is placed with its bottomed end directed upward; means for successively feeding said bottomed cylindrical objects along said first passageway from said receiving to said exit end thereof; a first air outlet formed in the bottom surface of said first passageway at a point intermediate between said receiving and said exit end thereof, said first air outlet being adapted to ascertain the presence of any defect in each of said bottomed cylindrical objects traveling thereover by delivering air therein at a prescribed pressure; a second passageway branching off from said first passageway at a point on the downstream side of said first air outlet; a second air outlet for delivering a forced current of air across said first passageway whereby said bottomed cylindrical objects can be directed into said second passageway; and a pneumatic circuit associated with said first and second air outlets, said pneumatic circuit being effective to cause said second air outlet to direct only a predetermined one of defective and non-defective classes of said bottomed cylindrical objects into said second passageway while the other class of said bottomed cylindrical objects are allowed to travel to said exit end of said first passageway.
 2. The apparatus as recited in claim 1, wherein said pneumatic circuit comprises: a source of compressed air; first pressure regulating means for regulating the pressure of the air from said source; a first conduit communicating said first pressure regulating means with said first air outlet; second pressure regulating means for regulating the pressure of the air from said source; control valve means communicated with said second pressure regulating means, said control valve means being normally closed; a second conduit communicating said control valve means with said second air outlet; and fluidic circuit means effective to open said control valve means in response to the development of a back pressure in said first conduit; whereby only non-defective ones of said bottomed cylindrical objects are directed into said second passageway by the forced current of air delivered out of said second air outlet.
 3. The apparatus as recited in claim 1, further including pressurizing feed means for feeding each of said bottomed cylindrical objects at least over said first air outlet in close sliding contact with the bottom surface of said first passageway, said pressurizing feed means comprising a roll rotatably supported above said first passageway, and drive means for imparting rotation to said roll.
 4. The apparatus as recited in claim 3, wherein the position of said roll is variable toward and away from the bottom surface of said first passageway to adjust to the varied height of the bottomed cylindrical objects to be sorted by the apparatus. 